Beta-arrestin-dependent parathyroid hormone-stimulated extracellular signal-regulated kinase activation and parathyroid hormone type 1 receptor internalization

Endocrinology. 2007 Aug;148(8):4073-9. doi: 10.1210/en.2007-0343. Epub 2007 May 24.


PTH regulates renal calcium homeostasis by actions on the distal nephron. PTH-induced calcium transport in mouse distal convoluted tubule (DCT) cells requires activation of ERK1/2. ERK activation by beta-adrenergic receptors occurs in a biphasic manner and involves receptor internalization. An early rapid phase is beta-arrestin (betaAr) independent, whereas prolonged activation is betaAr dependent. We characterized PTH-stimulated ERK activation and the involvement of receptor internalization and betaAr dependence. In DCT cells, PTH transiently activated ERK maximally at 5 min and then returned to baseline. betaAr dependence of PTH receptor (PTH1R)-mediated ERK stimulation was assessed using mouse embryonic fibroblasts (MEFs) from betaAr1- and -2-null mice. In wild-type MEFs, PTH(1-34)-stimulated ERK activation peaked after 5 min, was 50% maximal after 15 min, and then recovered to 80% of maximal stimulation by 30 min. In MEFs null for betaAr1 and -2, PTH-stimulated ERK activation peaked by 5 min and returned to baseline. The effect was identical in betaAr2-null MEFs. In betaAr1-null MEFs, ERK exhibited delayed activation and remained elevated. PTH-stimulated ERK activation and receptor endocytosis were not inhibited by the clathrin-binding domain of betaAr1 [Ar(319-418)]. Coexpression of the sodium proton exchanger regulatory factor 1 (NHERF1) with Ar(319-418) blocked PTH1R internalization. We conclude that PTH-stimulated ERK activation in DCT cells proceeds with a rapid but transient phase that may involve betaAr1. Furthermore, the betaAr-dependent late phase of ERK activation by PTH requires the participation of betaAr2 and PTH1R internalization.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Arrestins / genetics
  • Arrestins / metabolism*
  • Calcium / metabolism
  • Cells, Cultured
  • Endocytosis / physiology*
  • Fibroblasts / cytology
  • Kidney Tubules, Distal / cytology
  • Mice
  • Mice, Mutant Strains
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Parathyroid Hormone / metabolism*
  • Phosphorylation
  • Receptor, Parathyroid Hormone, Type 1 / metabolism*
  • Signal Transduction / physiology
  • beta-Arrestins


  • Arrestins
  • Parathyroid Hormone
  • Receptor, Parathyroid Hormone, Type 1
  • beta-Arrestins
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Calcium